Can my employer compel me to work 7 days a week without granting him any rest days?

As an employee in Hong Kong under a continuous contract, you are entitle to 1 rest day every 7 days. A rest day is a continuous period of 24 hours during which you are entitled to abstain from working for your employer

If your rest day is not fixed, the employer should inform you before the beginning of each month, of your rest days in that month.

Your employer may, with your consent, substitute some other rest day within the same month before your appointed rest day, or within 30 days after your appointed rest day.

Your employer may not force you to work on your rest day except if there is an emergency. In such situation the employer is required to substitute another rest day within the next 30 days.